Transmitted information may include a clock pattern, a synchronization pattern, or other non-random pattern with respect to channel adaptation. Such transmitted information may likewise include data, which is generally a random pattern with respect to channel adaptation. A receiver, which may be a standalone receiver or a receiver of a transceiver, receives such information and may include one or more adaptation loops for channel adaptation. Generally, channel adaptation includes adjusting a receiver to a channel. More particularly, channel adaptation may include adjusting filter tap coefficients for a channel impulse response. Such channel adaptation loops produce incorrect results when information is non-random.
Heretofore, for correlation, a receiver would include a plurality of correlators, such as a bank of correlators, where each correlator was configured for a different non-random or fixed pattern. For example, if there were 10 known fixed patterns in serialization-deserialization of information, then there would be 10 corresponding correlators configured to detect a respective one of such fixed patterns. Examples of such fixed patterns may include K28.5, DCom, EyeH, and RPAT, among other patterns. Once one of such correlators detected a known fixed pattern, one or more channel adaptation loops would be controllably frozen so as not to diverge responsive to trying to adapt to such fixed pattern. This freezing of one or more channel adaption loops may be set to a fixed time (e.g., frozen for a minute or some other time before releasing a channel adaptation loop), and such time may be programmably be set by a user. However, having a bank of correlators consumes a significant amount of resources, such as power and/or semiconductor area. Furthermore, freezing adaptation loops for a fixed time may exceed the amount of time a fixed pattern is being received, and thus an adaptation loop may be frozen for a longer time than necessary. Separately or additionally, a transmitter may send a fixed data pattern for a longer time than conventionally specified, such as by a standard communication protocol or other communication specification.
Hence, it would be desirable and useful to provide channel adaptation that overcomes one or more of the above-described limitations.